It is expected that a long term evolution-advanced (LTE-A) system, which is the standard of the next generation wireless communication system, will support a coordinated multi point (CoMP) system and a multi user-MIMO (MU-MIMO) system, which have not been supported by the existing standard, so as to improve a data transmission rate. In this case, the CoMP system means that two or more base stations or cells perform communication with a user equipment located in a shaded zone by coordinating with each other to improve communication throughput between the base station (cell or sector) and the user equipment. Examples of the CoMP system may include a coordinated MIMO type joint processing (CoMP-JP) system through data sharing and a CoMP-coordinated scheduling/beamforming (CoMP-CS) system. According to the joint processing (CoMP-JP) system, the user equipment may simultaneously receive data from each base station that performs CoMP, and may improve receiving throughput by combining the signals received from each base station. Unlike the joint processing system, according to the coordinated scheduling/beamforming (CoMP-CS) system, the user equipment may momentarily receive data from one base station through beamforming. The MU-MIMO technology means that the base station allocates each antenna resource to different user equipments and selects and schedules a user equipment that enables a high data transmission rate per antenna. This MU-MIMO system is to improve system throughput.
Meanwhile, with the widespread popularization of portable devices such as a smart phone, the amount of radio data has been increased rapidly, whereby a mobile communication network optimized on the basis of voice service has been required to be advanced on the basis of data service. For this reconfiguration of the radio network, additional facility of a base station is required. In this case, huge financial resources are required.
In this respect, a remote radio head (RRH) has been devised as one of methods for providing radio data services of high rate while minimizing the cost required for an advanced communication network. In an environment where RRH has been recently introduced, a user equipment may transmit an uplink signal to a base station or RRH. At this time, a detailed method for enabling a user equipment to determine an uplink transmission power has not been studied.